One task in poultry processing plants is removal of feathers from poultry prior to subsequent processing of the poultry. Automatic defeathering machines have achieved widespread use in removing feathers from poultry. Such defeathering machines include a plurality of picking fingers which are rotated so as to impact the poultry suspended on a conveyor line moving through the defeathering machine. As the rotating fingers impact the poultry, the feathers are removed.
Typically, a plurality of picking fingers are mounted to a mounting plate, which may be in the shape of a disk or a drum. Picking fingers include a base or mounting portion and a tapered ribbed defeathering portion extended from the base portion. The base portion includes circular mounting groove. The mounting plate includes a plurality of circular openings. To install a picking finger in a mounting plate circular opening, the tapered defeathering portion is inserted from a back side of the mounting plate through a circular opening in the mounting plate. The outer diameter of the base of the picking finger is slightly larger than the diameter of the mounting plate circular opening, while the diameter of the mounting groove is about the same size as the diameter of the circular opening. The picking finger is then pulled forward, the base of the finger contacting, stretching and being pulled through the mounting plate opening until the groove pops or snap fits into the circular opening. The picking finger groove seats against a peripheral edge of the mounting plate defining the opening thereby holding the picking finger in place with respect to the mounting plate.
A defeathering machine will typically include two or more rows of mounting plates bordering each side of a path of travel through the machine. The mounting plates are rotated thereby rotating the picking fingers mounted to each plate. The picking fingers are mounted in the mounting plates and the mounting plates are oriented such that the picking fingers impact the poultry during rotation of the mounting plates. A typical defeathering machine may have 3,000 or more picking fingers. The picking fingers are subject to a water spray to rinse off the feathers as they accumulate on the fingers.
The picking fingers are typically made of resilient rubber material or rubber-like plastic material. Depending on the poultry being processed, different sizes and shapes of picking fingers are used. As the picking fingers are used, they are rotated and subject to centrifugal force, they also impact the poultry and are sprayed with water. Over time, the elasticity of the rubber decreases and the fingers become less efficient in removing feathers. Sometimes, the fingers break off in use. In either event, picking fingers have to be removed from their respective mounting plates and replaced on a regular basis.
Removal and replacement of picking fingers is a difficult and labor intensive job. If done manually, an upper or defeathering portion of the finger to be replaced is bent sideway with respect to the mounting plate and a razor blade knife is used to cut the finger at its base adjacent the mounting plate. The dangers of using a razor blade knife to cut the base of the finger while simultaneously bending the upper portion of the finger are self-evident. A new picking finger is then inserted from the back side of the mounting plate through an opening in the mounting plate as described above. Because there is an interference fit between the base portion and the mounting plate opening, a tool such as a pair of pliers must be used to forcibly pull on the defeathering portion of the finger to pull the base portion though the opening until the base portion groove snap fits into the circular opening. A prior art picking finger 10 mounted to a mounting plate 12 is shown in FIG. 1. As can be seen in FIG. 1, the finger 10 has a base portion 14 including an annular groove 16. The finger 10 is inserted from a back side B of the mounting plate 12 and pulled through a circular opening 18 in the mounting plate. The finger 10 is pulled in the forward direction F by pliers T until the groove 16 snap fits into the mounting plate opening 18.
In order to aid in the insertion of the picking fingers into the mounting plate, prior to installation, the fingers are typically soaked in water or lubricated with soap or similar lubricant. Even with the application of lubricant, installation of picking fingers is problematic because significant force is required to pull the finger base portions through the circular openings to achieve the snap fit of the annular groove in the circular opening. This problem is further exacerbated because, due to the design of defeathering machines, the positioning of mounting plates within the machine and the plurality of picking fingers on each mounting plate, there is little clearance available for removing and/or inserting picking fingers.
Power tools have been developed to aid in the removal of old picking fingers and the insertion of new fingers to a mounting plate. Picking finger cutters provide a cutting edge for cutting an old finger while picking finger installers provide a vise grip to grab and pull a new finger through a mounting plate opening. Aside from the expense, such tools have numerous disadvantages. Such tools are typically pneumatically powered and require a source of compressed air. Further, such tools require operators to drag an air hose into a production area to operate the tools thereby risking contamination of the area. Such tools are typically heavy and cumbersome to use. As such, power picking finger cutters and installers have not been widely adopted in the poultry processing industry.
What is desired is a picking finger having a mounting structure that provides for quick and secure attachment of the picking finger to the mounting plate. What is also desired is a picking finger having a mounting structure that provides for quick and easy removal of the picking finger from the mounting plate without the necessity of cutting the finger. What is also needed is a picking finger that can be removed and installed without the necessity of heavy and burdensome power tools.